Chemical apparatus.



B.B;ELDRED.

CHEMICAL APPARATUS.

APPLICATION FILED JAN. 7, 1908. RENEWED MAY 9, 1912.

Patented Nov. 5, 1912 est: 6 glnventor:

. 7AM 5 4w! 3 by 074 8 M A ttys UNITED sures Parana? OFFICE.

BYRON E. ELDRED, OF BRONXVILLE, NEW YORK, ASS IGNOB TO THE COMMERCIAL-RESEARCH COMPANY, OF NEW YORK, N. Y., A CQRPORATION OF NEW YORK.

CHEMICAL APPARATUS.

Patented Nov. 5, 1912.

Application filed January 7, 1908, Serial No. 409,623. Renewed May 9,1912. Serial No. 69%,280.

To all whom it may concern.- I

Be it known that I, BYRON E. ELDRED, a citizen of the' United States,resi ing at Bronxville, in the county of Westchester and State of NewYork, have invented certain new and useful Chemical Apparatus; and I dohereby declare .the following to be a full, clear, and exact descriptionof the same, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to chemical apparahis and consists in anevaporating pan or still lined with a noble metal in the form of animpervious, poreless film and having a body of a strong and stiffferrous metal to which said film lining is attached in heat conductingrelationship by a strong and indissoluble union in the nature of a Weldunion; all as more fully hereinafter set forth and as claimed.

- For many purposes, as in evaporating and distilling such corrosivesubstances as ,sulfuric acid it is desirable to have relatively largevessels madei of the resistant noble metals like gold andplatinum. Bothgold and platinum however are relativelyweak, soft metals'and aside fromthe question of their cost, it is impracticable to make very largevessels of either. Platinum further suffers from the disadvantage thatit "is at-' tacked more or less by reducing and smoky flames,particularly if, in contact with silicious material or dust, renderingfire heating of platinum pans disadvantageous.

It is the purpse of the present invention for such lining, weld-unitedthereto and --thoroughly supporting the same; such backing layercomprising a ferrous metal such as iron or steel. There is of course nodiflicylty in making vessels of sufficient strength in any size'fromsteel or iron, and the same is true of gold or platinum filmed iron orsteel. Preferably, further, this backing layer of ferrous material isprovided with a layer of another and heat conductive metal on theexterior where the vessel is to be used with fire heat.

For concentrating sulfuriciacid, a usefulform'of pan or still under the.present invention may be produced from sheet steel or iron lined on oneside with a Welded-on film-like layer of goldor platinum and on cutarticle.

the other with a thicker layer of copper,

similarly weldedjon. Sulfuric acid is a 'difli-' cult liquid to heat,its convection being slow so that it d0es not rapidly take up heat fromheated surfaces or heat uniformly.

Platinum being a. relatively poor conductor of heat in a platinum pan itis difficult to heat a mass of sulfuric acid uniformly, a spot of extraheat on the bottom of such a pan not tending to equalize laterally 01'to be dissipated by the convection of the acid.

In using such platinum pans it is therefore thoroughly welded to thesteel at all abut- .tingsurfaces, so as to insure good metallic contact,all portions of such platinum layer willLbe maintalned at-an equalizedheat. Impmgement of flame on a steel surface In the composite pan of.the present is not so dangerous as impingement upon a platinumsurface.In the preferred form (if the present invention stated, however, the

steel is covered on the under side b a welded-on layer of copper andthis layer is at once better adapted for flame impingement than iron andis a better conductor for heat; 2'. e., operates even better inproducing a lateral equalization of temperature.

Steel havingv welded-on coatings of copper of any thickness desiredmaynow be pro-- duced under the process patented to J. F. Monnot (PatentNo." 853,716) and such ma terial may well be used to produce the pres-The-copper coating in billets made by the stated process is,indissolubly united to the steel by a'union resisting dis .c0veryby-cutt-ing tools, such as cold chisels,

by violent changes of temperature, such 'as heating and quenching,-orby. flexion; The

joined metals are toaall intents and purposes, or are actually,"weldedtogether, and are of course in perfect metallic heat transmittingrelationship. Bars of such Monnot metal having copper or silver on bothsides may be heated until the coating metal is somewhat softened and maythen be contacted, with bodies of gold or platinum under pressure untilunion is effected, whereupon the new billet may then be rolled out intosheets and shaped to form the articles of the present invention, theside of the sheet carrying the noble metal being of course used for theinside of the chemical vessel. Instead of using solid bodies of gold orplatinum, these metals may be applied to the copper or silver in amolten state,

. above its melting point, or fluidl this having the advantage offorming absolutely poreless coatings. Fluid gold or platinum may be aplied to the clean naked steel, the gold being preferably heated muchiron may be contacted with the noble meta in a solid state. rBut gold orplatinum united. to Monnot' metal carrying copper or silver coatingsgives an article satisfactory for the present purposes.

' contact with it.

However shaped, the chemical vessel underthepresent invention preferablyhas the noble metal lining extended over its mouth or opening in suchmanner as to prevent liquids gaining access capillarily to the morecorrosible exterior metal, but in no case should the noble metal extendsufficiently far to cont-act with settings or supports, or, in the caseof a platinum layer, should it come where impinging flame, may

Sulfuric acid pans for concentratingacid may advantageously beconstructed with overhangin edges having the noble metal covering suchedges.

In the accompanying drawing I show an evaporating pan constructed asabove described, the figure showing a vertical section thereof.

In said drawing, 1 designates the base of strong metal, such as iron orsteel, 2,' 2, coatings of another metal, such as copper or.

silver, weld-united to the metal 1, and 3 alayer of metal, such as goldor platinum,

which is relatively unaffected by chemicals,

weld-united to the metal 2. As shown, the

metals 2 and 3 are drawn over the edges of the metal 1, to avoidchemical attack thereon.

It is obvious that various other chemical receptacles and other chemicalapparatus may be constructed-of the same weld-united layersof strongmetal and chemically-inactive metal.

What I'claim is i 1. A chemical vessel adapted for theevaporation ofcorrosive liquids and having an impervious lining of a-noble metal anda'thicker strengthening body of a ferrous metal, the two metals beingmetallically united and in heat-conducting relationship at all pointsand saidvessel teI1QI"]\}lll adapted to receive from said noble metal.

2. A chemical vessel adapted for theevaporation of corrosive liquids andhaving an heat and free impervious lining of a noble metal, a thickerstrengthening body of a ferrous metal, and an exterior layer of a metalconducting heat freely, the several layers being metallically united andin heat conducting relationship at all points.

3. A chemical vessel adapted for the evaporation of corrosive liquidsand having an impervious lining of a noble metal united to astrengthening body of ferrous metal by a linking layer of another metal,said metals being metallically united and in heat conductmg relationshipat all points and said vessel having an exterior wall adapted to receiveheat and free from said noble metal.

4. A chemical vessel adapted for the evaporation of corrosive liquidsand having an impervious lining of noble metal united to a strengtheningbody of ferrous metal by a linking layer of another metal, said ferrousthereto and in uniform heat conducting relationship therewith, said panhaving an overhanging edge forming a reentrant angle and said liningextending over the edge and terminating in said reentrant angle.

7. An evaporating pan having a body of ferrous metal and an imperviouslining layer of noble metal'metallically united thereto ai ld in uniformheat conducting relationship therewith, said pan having an overhangingedge forming a reentrant angle and sai lining extending over the edgeand terminating in said reentrant angle, said body of ferrous metalbeing provided also on the under 'side' of the pan with a metallicallyunited layer of arelatively better heat-con ducting metal.

. 8. An evaporating .pan having body of ferrous .metal, a limng of goldmetallically united thereto, and a layer of copper weldunited to theunder side of said ferrous metalbody. I

In testimony whereof I aflix my signature,

"inthe presence of two Witnesses; having an exv K BYRON E. ELD REDr.

.' Witnesses: i i i J. F. MoNNo'r, H. M. MARBLE.

